1. Field of the Invention
The present invention relates to a mobile telephone repeater comprising an uplink for amplifying signals from a mobile telephone to a base station and a downlink for amplifying signals from said base station to said mobile telephone, said two links being provided with a number of parallel amplifier chains, each amplifier chain being designed to pass through a specific frequency band.
2. Description of the Related Art
A repeater for use in cellular telephone systems is a device which amplifies a received RF-signal and retransmits the amplified signal at same carrier frequency. Normally, a repeater is operative in a rather broad spectrum of radio frequencies in the order of 1-2 GHz. Often, a repeater will serve several telephone system operators, each operator being assigned a specific frequency band within the broad range of frequencies handled by the repeater. Alternatively, an operator may have his own repeater and use various parts of the available frequency range for different purposes.
In any case there is a general demand for flexibility in terms of changing the frequency bands, both in terms of centre frequency and bandwidth. Such changes may be a consequence of permits given by the authorities or by technological changes. Also, operators may leave the scene or new ones may be added.
Accordingly, there is a demand for frequency band changes in one or more of the amplifier chains of the repeater.
Of course, such changes may be effected by changing the hardware components of the repeater, such as filters or the like. However, such hardware changes will normally be cumbersome and fairly costly. Furthermore, repeaters may be mounted at remote locations, whereby hardware replacements will be particularly expensive.